The prior tractor art is already aware of various arrangements for hand controls for the powered units commonly mounted on and employed in a tractor. These units include hydraulic elements, such as transmissions and valves for actuating parts on the tractor and including a brake. Further, the prior art units of which this invention is concerned are of the tractor environmental type and including the so-called skid steer type of loaders which require special levers and linkages for operating the hydraulic valve spools and the hydrostatic transmission pumps. Traditionally, the prior art has achieved its functions with the use of levers attached to a cross-shaft with handles attached to the other ends of the levers, all for operating the transmission and a hydraulic valve, for instance.
One of the problems with regard to the prior art is the fact that the tractor or loaders inherently have a limited space for the operator's compartment, and thus the projecting handles and levers are usually occupying valuable space which is required for movement of the operator into and out of the operator's compartment. In some respects, the prior art handles and levers must necessarily be arranged, due to their particular shape and system structure, so that they project into the path which the operator would normally move along in getting into and out of the operator's compartment. As such, the operator could accidentally bump these handles and move them to undesirable positions at that particular moment. Still further, the prior art control systems are of a limited nature in that they control only some of the powered units mentioned, and one handle usually is not capable of controlling all of the powered units, such as hereinafter described with regard to this invention.
Accordingly, it is an objective of this invention to improve upon the prior art control systems, and, more specifically, the present invention provides a single handle control system which operates the several powered units including the transmission, hydraulic valve, and the brake.
One specific object and advantage of this invention is to provide a control system for a tractor having powered units to be operated, and wherein the system controls several units by means of a single handle and different directions of maneuvering the single handle and wherein the handle portion of the control system can be moved to an inoperative and thus safe position where the system cannot inadvertently be operated and wherein the projecting portions of the system are out of the way of the operator who can thus freely move into and out of the operator's compartment. In accomplishing the aforementioned objects and advantages, the present invention provides a control system which is reliable in its function and which is sensitive so that all movements in the several directions create operation of the powered units attached to the system, and yet there are only a minimum of parts which are easily maneuvered and are sturdy and reliable in their function.
Even more specifically, the present invention provides a control system for operating the transmission of a tractor, such as a skid type of tractor which has separate power control of the left and right wheels on the tractor and thus two control handles are utilized and the movements thereof are in the horizontal plane which results in less operator fatigue and which permits a more natural movement and which also provides for greater variations in the design of the operator's compartment and the arrangement of other structural parts therein.
Other objects and advantages will become apparent upon reading the following description in light of the accompanying drawings.